Crush Zone Size Dependence On Charge Size

A series of two dimensional model tests were conducted to determine the size of the crushed zone as a function of charge size. The intent was to investigate the idea that it is impossible to transmit from an explosive source a stress wave of greater magnitude than the compressive strength of the material. Tests were conducted in 2-D models made from PMMA and Homolite 100 sheets with charge masses ranging from 174 mg to 600 mg of PETN. A dynamic polariscope was used to record the isochromatic fringe patterns which were then used to determine radial and tangential stresses propagating out into the model from the explosive source. The crush zone size caused by the detonation of the explosive charge was measured after the tests and compared to the transmitted stress as well as the charge mass.